Three men are buried in the sand all facing forwards with their heads above ground.

Each man has a hat placed on his head selected from a bag containing 3 red hats, and 2 black hats, and the men knew the possible hat choices.

The men cannot turn around to see the men behind them.

The man at the back is asked what hat he is wearing. He replies 'I do not know'. The middle man is asked what hat he is wearing. He also replies 'I do not know'. The man at the front is then asked what hat he is wearing. He replies 'I am wearing a red hat'.